Enzymes which digest proteins are widely distributed in nature. Both intracellular and extracellular proteases exist in a wide variety of organisms. Extracellular proteases are produced by micro-organisms to enable them to convert proteinaceous material to low molecular weight peptides for transport into the cell, to satisfy either carbon and energy requirements and/or nitrogen requirements for growth. Bacteria, fungi and yeasts are known to produce different proteases, both intracellular and extracellular, whose biochemical characteristics and properties have been described; see e.g. The Enzymes, Ed. Paul D. Boyer Vol. III "Hydrolysis: peptide bonds". 3rd Edition 1971.
We have now found it possible to produce extracellular proteases from Micrococcus sedentarius which are capable of solubilizing human callus material and degrading other proteinaceous material.